Book Claims Johnny Carson Was Targeted By Mafia

That's the stunning revelation in Johnny Carson, the new tell-all book.

It happened in 1970 after Carson apparently made a pass at a mobster's girlfriend at a New York bar. These days it's known as the Russian Samovar, but back then it was Jilly's Saloon, a known mob hangout.

The new book claims the mobster and his goons grabbed Carson off his bar stool and threw him down a flight of stairs. Then, they supposedly put a contract out on the talk show host's life.

"Taking the threat seriously, Carson holed up in his U.N. Plaza palace for three days, missing three shows," writes Bushkin.

The gangsters called off the hit after Carson arranged for TV coverage of a 1971 Italian-American unity rally in New York.

Another explosive claim in the book is coming uder fire today. Bushkin says Carson was convinced his second wife, Joanne, was having an affair with sports caster Frank Gifford. Gifford denies the affair and Joanne Carson also says it never happened.

But a woman who identitified herself as Joanne's ex-secretary says the affair really happened. Margaret Davies told the New York Post, "Joanne was a manipulative twit. She was a liar."

Joanne says she never heard of Margaret Davis.

"She never worked for me. This is ludicrous and it's not true," said Joanne.

Veteran talk show host Dick Cavett got an advance copy of the book, which is being released next week.

Cavett told INSIDE EDITION, "There's a lot of unpleasant stuff in the book. It seemed straightforward and probably factual."

Cavett knew Carson for 30 years and says the talk show legend was a tortured soul.

"He was one of the most uncomfortable men I've ever known in himself, and in social situations. With all of that suffering he went through, he was dazzling on the air," said Cavett.